Reconfigurable true-time delay for wideband phased-array antennas

Abstract

A novel reconfigurable true-time delay feed for phased-array antennas working from X to Q (8-50GHz) frequency bands is presented. The reconfigurable optical true-time delay feed, employing monolithic integration of polymer waveguide delay lines and polymeric optical switches, has great advantages in providing power efficient, lightweight, and small size features. Optical switch technique provides large delay selections enabling the module to operate in ultra-broad radar bands. Polymer waveguides with optical propagation loss of less than 0.9dB/cm were achieved at 1550nm. 2X2 thermo-optic switchs as fast as 1ms were fabricated with an excess insertion loss of 0.5 dB in the "switching state" and 1.5dB in the "non-switching state". Reconfigurability of the true-time delay line was demonstrated through accurate time delay measurement.

RF Engineering Meets Optoelectronics: Progress in Integrated Microwave Photonics

“…Higher delay resolution (required for antennas operating at high frequency) can also be improved with an integrated photonics approach. A number of photonic integration platforms have been used, such as polymer technology [37]- [39], silica [40]- [43], LiNbO 3 [44], GaAs [45], [46], and InP [47], [48]. A recent example [49] using ultralow-loss Si 3 N 4 substrate showed a fully integrated 4-bit TTD line capable of delays above 12 ns, corresponding to about 2.4 m of propagation length, on a chip area of 4.5 cm # 8.5 cm, with waveguide losses as low as 1 dB/m (Figure 7).…”

Reconfigurable thermo-optic polymer switch based true-time-delay network utilizing imprinting and inkjet printing

“…With these special features, TO polymer switches have enabled widespread applications in several areas, such as communication and radar, add/drop multiplexing, bypass switching in the event of a network failure or network jam, packet switching, etc. [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. However, until now, the most common methods for polymer optical device fabrication includes either using Reactiveion Etching (RIE) to define the pattern into a resist, and transferring the pattern to the optical polymer via plasma etching [21,22], or directly writing the pattern in a low-loss UV/Ebeam curable polymer using lithography [18,20].…”

“…In this work, we demonstrate the feasibility of developing very large-area photonic systems. Specifically, a complete 4-bit true-time-delay reconfigurable module with a dimension of 25 mm × 18 mm, comprising of an array of five interconnected TO switches and polymer delay lines [9][10][11][24][25][26][27], is developed. Thanks to the roll-to-roll (R2R) compatibility of the employed solution processing techniques, photonic system development over large areas on either rigid or flexible substrates, and at high-throughput, is possible which will lead to tremendous cost savings.…”

Reconfigurable Thermo-Optic Polymer Switch Based True-Time-Delay Network Utilizing Imprinting and Inkjet Printing

“…Specifically, reconfigurable true-time-delay (TTD) lines comprising of TO switches and rib waveguides, are able to deliver precise delays for phased array antenna (PAA) applications [1][2][3][4][5][6].…”